JP3679633B2 - Electrostatic transfer device and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrostatic conveyance device that conveys an electrostatic force and an image forming apparatus including the electrostatic conveyance device.
[0002]
[Prior art]
Conventionally, an electrode group is formed in a strip shape as shown in FIG. 4, for example, on a conveying belt as a moving body, conductive brushes are provided at both ends of the conveying belt, one is connected to the ground potential, and a predetermined voltage is applied to the other. There is a method in which a potential difference is generated by application to obtain an electrostatic force to adsorb the conveyed object. As shown in FIGS. 4 (a) and 4 (b), a plan view and a side view are shown in a comb-like shape on the surface opposite to the transport surface of the dielectric film layer 9 serving as the base of the transport belt, for example, having a thickness of 35 μm and a width of 8 mm An electrode group 10 is provided in which electrodes are arranged with a gap of 8 mm on the surface. In the electrode group 10, the power feeding portions 4 a and 4 b are placed so as to be in contact with the ends of the alternating electrodes 10 a and 10 b. FIG. 3 is a cross-sectional view of the conveyor belt and the power feeding unit. Reference numeral 13 denotes a conductive brush. Reference numeral 12 denotes a base material for planting the conductive brush that supplies power while being in contact with the electrode group of the conveyor belt of the power feeding unit 4. FIG. 2 is a schematic diagram of a power supply brush which is a power supply unit. In this example, the power feeding unit 4b is grounded. In order to obtain an electrostatic force, a voltage of about 1 to 2 KV is applied to the power supply unit 4a. When the conveyor belt rotates, the electrode group on the conveyor belt slides into contact with the brush and receives power to generate an electrostatic force. The to-be-conveyed body is brought into close contact with the conveying belt by electrostatic force and conveyed.
[0003]
[Problems to be solved by the invention]
In the above-described conventional conveying apparatus that attracts and holds the object to be conveyed by electrostatic force, the conductive brush whose power source is a power supply unit according to the movement of the conveying belt from the upstream side in the conveying belt moving direction. When approaching and coming into contact, a high voltage is suddenly supplied, so that the voltage difference between the brush and the electrode group may be large and discharge may occur. When a discharge occurs, it not only emits electromagnetic waves and becomes a noise source, but also causes a malfunction. Moreover, there was a risk of causing a spark and damaging the contact portion between the electrode group on the conveyor belt and the brush, thereby significantly shortening the service life. Further, in a conventional conveyance device that holds an object to be conveyed by electrostatic force, an electric field for adsorption may adversely affect, for example, a recording head or a sensor disposed close to the conveyance belt.
[0004]
The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide an electrode group provided on a moving body that moves by electrostatically attracting a transported body, and an electrode group. It is an object of the present invention to provide an electrostatic transfer device that prevents electric discharge when the power supply means that contacts and applies a voltage is brought into contact with the movement of a moving body, and that reduces noise generation and contact damage.
[0005]
It is another object of the present invention to provide an electrostatic transfer device that can reduce an electric field only in the vicinity of a portion affected by an electric field for adsorption without significantly reducing the electrostatic attraction force.
[0006]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a first electrode group comprising a moving body that moves in a transport direction of a transported body, and a plurality of electrodes that are provided in the transport direction in the transport body and that move with the mobile body. And a plurality of other electrode groups that are provided in the moving direction in the transporting body, move together with the moving body, and have a potential difference with the first electrode group, and the first electrode group and the other In the electrostatic transport apparatus that transports the transported object by attracting the transported object to the moving body with an electrostatic force generated by a potential difference between the first electrode group and the electrode group, the first moving part of the moving body on the moving path is moved . 1st electrode group electric power feeding means which applies a voltage in contact with the electrode of 1 electrode group, The said 1st electrode group electric power feeding means has the electric potential gradient of the moving direction of the said mobile body, and with respect to said 1st electrode group And inducing a potential having a gradient in the moving direction. .
[0007]
In this way, since the potential difference when the first electrode group provided on the moving body moves and contacts the first electrode group power supply means can be reduced, the first electrode group and the first electrode group power supply means can be reduced. The occurrence of inrush current and electric discharge at the time of contact with can be prevented, and as a result, generation of noise and damage to the contact portion can be reduced. Further, since the static electricity can be gradually removed when the first electrode group is detached from the first electrode group power supply means, it is not necessary to provide a means for eliminating static electricity separately. In addition, the electric field can be reduced only in the vicinity of a portion affected by the electric field for adsorption without significantly reducing the electrostatic adsorption force.
[0008]
The potential gradient may be provided in the vicinity of the most upstream end, the most downstream end of the first electrode power supply means, or a portion where it is desired to avoid the influence of the electric field.
[0009]
In addition, the first electrode group may include an electrode small group composed of a plurality of electrodes provided close to each other in the moving direction.
[0010]
In this way, since the electrode subgroups are close to each other in the moving direction, the potential gradient in the moving body direction of the first electrode group feeding means is faithfully reflected by the potential gradient of the first electrode group.
[0011]
Further, the first electrode group power supply means may have a potential gradient in the moving direction at one or a plurality of positions in the moving direction.
[0012]
As described above, the potential gradient of the first electrode group power supply means may be provided at one place in the moving direction, or a plurality of electric field gradients may be provided in the vicinity of a portion that is easily affected by the electric field on the moving path of the moving body. The same effect can be obtained even if it is provided at a location.
[0013]
The first electrode group power supply means includes a plurality of conductive contact power supply members that are in contact with the first electrode group and an extension in the moving direction, and applies a voltage to the contact power supply member. A holding base material for holding, and a plurality of connection terminals for supplying a predetermined voltage to the holding base material, applying different voltages from the plurality of connection terminals, and at least the movement of the holding base material A portion that generates a potential gradient in the direction may be formed of a material having a large specific resistance.
[0014]
If it does in this way, the electric potential gradient of a moving direction can be produced by the voltage drop of holding | maintenance base material itself to which a voltage is supplied with a some connection terminal.
[0015]
Further, a plurality of power supplies may be connected to the plurality of connection terminals.
[0016]
Any of the connection terminals may be grounded via a resistor.
[0017]
In this way, a predetermined voltage can be supplied without connecting a power source to the connection terminal.
[0018]
In addition, the other electrode group contacts a second electrode group power feeding unit different from the first electrode power feeding unit in a part of the moving path of the moving body, and is grounded through the second electrode group power feeding unit. A second electrode group consisting of a plurality of electrodes may be included.
[0019]
The other electrode group is in contact with a second electrode group power feeding means different from the first electrode group power feeding means in a part of the moving path of the moving body, and a predetermined voltage is applied by the second electrode group power feeding means. A second electrode group to which is applied may be included.
[0020]
The other electrode group is in contact with a second electrode group power feeding means different from the first electrode group power feeding means in a part of the moving path of the moving body, and a voltage is applied by the second electrode group power feeding means. The second electrode group feeding means has a potential gradient in the moving direction of the moving body, and induces a potential having a gradient in the moving direction with respect to the second electrode group. It may be.
[0021]
In this way, since the potential difference when the second electrode group provided on the moving body moves and contacts the second electrode group power supply means can be reduced, the second electrode group and the second electrode group power supply means can be reduced. The occurrence of inrush current and electric discharge at the time of contact with can be prevented, and as a result, generation of noise and damage to the contact portion can be reduced. Further, since the charge can be gradually removed when the second electrode group is detached from the second electrode group power supply means, it is not necessary to provide a means for removing electricity separately. In addition, the electric field can be reduced only in the vicinity of a portion affected by the electric field for adsorption without significantly reducing the electrostatic adsorption force.
[0022]
The potential gradient may be provided in the vicinity of the most upstream end, the most downstream end of the second electrode power supply means, or a portion where it is desired to avoid the influence of the electric field.
[0023]
Of course, the second electrode group and the second electrode group power supply unit may be configured similarly to the first electrode group and the first electrode group power supply unit according to the present invention. Moreover, you may provide the electrode group different from a 2nd electrode group in another electrode group.
[0024]
Further, in an image forming apparatus having an image forming unit that forms an image on a recording medium and a conveying unit of the recording medium that has the image forming unit on a conveyance path, the recording medium is conveyed as the conveyance target. You may make it provide the electrostatic conveyance apparatus which concerns on any one of Claims 1 thru | or 8 as a conveyance means.
[0025]
In this way, while maintaining the suction force of the transport means, the unnecessary radiation, malfunction, and contact breakdown due to inrush current and discharge in the transport means are reduced, and adverse effects on parts that may be affected by the electric field are prevented. Therefore, it is possible to provide an image forming apparatus with high reliability and capable of high-quality image formation.
[0026]
Further, it is desirable that the first electrode group feeding unit has a potential gradient with a small electric field in the vicinity of the image forming unit .
[0027]
In this way, it is possible to prevent an adverse effect on the image formation due to the electric field of the transport unit while maintaining the suction force of the transport unit, and thus high-quality image formation is possible.
[0028]
Further, in an image forming apparatus having an image forming unit that forms an image on a recording medium and a conveying unit of the recording medium that has the image forming unit on a conveyance path, the recording medium is conveyed as the conveyance target. You may make it provide the electrostatic conveying apparatus which concerns on Claim 9 as a conveying means.
[0029]
In this way, while maintaining the suction force of the transport means, the unnecessary radiation, malfunction, and contact breakdown due to inrush current and discharge in the transport means are reduced, and adverse effects on parts that may be affected by the electric field are prevented. Therefore, it is possible to provide an image forming apparatus with high reliability and capable of high-quality image formation.
[0030]
In addition, it is preferable that at least one of the first electrode group feeding unit and the second electrode group feeding unit has a potential gradient with a small electric field in the vicinity of the image forming unit .
[0031]
In this way, it is possible to prevent the adverse effect on the image formation due to the electric field of the transport unit while maintaining the suction force of the transport unit, and therefore high-quality image formation is possible.
Moreover, it is desirable that the first electrode group power supply means has a potential gradient with a small electric field at the upstream end in the moving direction of the moving body.
In addition, it is preferable that at least one of the first electrode group power supply unit and the second electrode group power supply unit has a potential gradient with a small electric field at the upstream end in the moving direction of the moving body.
A plurality of conveyance belts that convey the recording medium; a plurality of first electrodes that are provided in the movement direction of the conveyance belt; and a plurality of electrodes that are disposed in the movement direction of the conveyance belt. A second electrode group that is arranged alternately with the electrodes of the group and moves with the belt, and a first electrode that applies a voltage to an electrode that moves in a predetermined section of the recording medium conveyance path among the electrodes of the first electrode group. In an electrostatic conveyance device that includes an electrode power feeding unit, and that attracts and transports the recording medium to the conveyance belt with an electrostatic force generated by a potential difference between the first electrode group and the second electrode group, the first electrode power feeding unit includes: A voltage is applied so that the electrostatic force at the upstream end of the predetermined section is reduced.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
Hereinafter, the present invention will be described in detail based on a first embodiment with reference to the drawings.
[0033]
FIG. 1 shows an example of a configuration applied to a so-called inkjet recording apparatus which is an image forming apparatus as a preferred embodiment of the present invention.
[0034]
The conveyor belt 2 as a moving body is driven by a driving roller 5 and is supported and rotated by support rollers 6, 7, and 8.
[0035]
Reference numeral 3 denotes an ink jet recording head as an image forming unit, which is driven by a control unit (not shown) to perform recording by discharging ink droplets. A transported body 1, which is a recording medium such as paper or a plastic sheet, is fed from a paper feeding unit (not shown), is electrostatically attracted to the transport belt 2, moves, and is recorded when passing under the ink jet recording head 3. Is done.
[0036]
The present invention is characterized in that the conveying belt 2 further divides each electrode in FIG. 4 of the conventional example into finer independent electrode groups in order to give the adsorption electrode a voltage gradient (potential gradient). That is, as shown in FIG. 5, each electrode 10a, 10b, which has conventionally been one, is divided into fine strips. FIG. 5 (a) is a plan view of the conveyor belt 2 showing this state, and 11a and 11b are electrode groups including a small electrode group consisting of finely divided electrodes. FIG. 5B is an enlarged view of the side surface of the conveyor belt 2. In the present embodiment, the power feeding unit 4b side is grounded. The cross-sectional views of the conveyor belt 2 and the power feeding units 4a and 4b are the same as those in FIG. In the present embodiment, the conveying belt 2, the driving roller 5, the supporting rollers 6, 7, 8, and the power feeding units 4a and 4b constitute an electrostatic conveying device and a conveying means.
[0037]
FIG. 6A is a conceptual diagram of a power supply unit (first electrode group power supply means) 4a that enables power supply with a voltage gradient to the divided electrodes. In the figure, reference numeral 12 denotes a base material (holding base material) on which the power supply brush (contact power supply member) 13 is planted, and a material having a high specific resistance value is used. When the connection terminals A, D, and G of such a power feeding unit are grounded and a power source is connected to the connection terminals B, C, E, and F, between AB, between CD, between DE, and between FG A voltage gradient occurs in FIG. 6B is a graph showing the relationship between the feeding position and the feeding voltage. This voltage is transmitted to the electrode group (first electrode group) 11a of the conveyor belt 2 from the power supply brush 13 of the power supply unit. Since the electrode group 11a is divided into fine strips, the voltage of the power feeding portion 4a appears as it is. Symbols A to G in the figure correspond to positions A to G in FIG. The base material 12 of the power feeding unit 4a may be made of a material having a low specific resistance value such as metal between B and C and between E and F.
[0038]
In this embodiment, since the power feeding part (second electrode group power feeding means) 4b is grounded, the electrode group (second electrode group, other electrode group) 11b is grounded, and a conventional electrode structure may be used. If the power supply unit 4b is grounded, a power supply brush similar to the conventional one can be used. On the other hand, it is natural that the present invention can be applied to a case where another predetermined voltage is applied without grounding the power feeding unit 4b or a voltage having a gradient is applied as in the power feeding unit 4a.
[0039]
In the present embodiment, the electrode group and the power feeding unit are installed on the surface opposite to the transport surface. However, the present invention can be applied to both the electrode group and the power feeding unit on either surface. Further, in the present embodiment, the power feeding unit is a brush, but other power feeding methods such as a roller do not depart from the spirit of the present invention.
[0040]
In the present embodiment, the ink jet recording apparatus that records an image by transporting a recording medium has been described. However, the present invention is not limited to this, and an image forming apparatus having a known image forming unit or a transported body is electrostatically connected. The present invention can be applied to an electrostatic conveyance device that conveys by an attractive force.
[0041]
(Second Embodiment)
FIG. 7A is a configuration diagram of the power feeding unit 4a according to the second embodiment. Since it has the same configuration as that of the first embodiment except for the configuration of the power feeding unit, the same reference numerals are used and description thereof is omitted.
[0042]
This is a system in which the second power supply is connected without grounding the ground locations A, D, and G of the connection terminal in FIG. The state of the power supply position and the power supply voltage at this time is shown in FIG.
[0043]
(Third embodiment)
FIG. 8A is a configuration diagram of a power feeding unit showing the third embodiment. Since it has the same configuration as that of the first embodiment except for the configuration of the power feeding unit, the same reference numerals are used and description thereof is omitted.
[0044]
The grounding portions A, D, and G of the connection terminal in FIG. 6 are configured to be grounded through resistors. The power supply position and the power supply voltage at this time are the same as in FIG. Also, if A, D, and G are not put together via a single resistor but are grounded separately via a resistor, a desired voltage can be obtained separately without preparing a plurality of power supplies. it can.
[0045]
【The invention's effect】
As described above in detail based on the embodiment shown in the drawings, according to the present invention, the first electrode group power supply means has a potential gradient in the moving direction of the moving body, so that the first electrode provided in the moving body is the first. The inrush current and discharge when the electrode group moves and contacts the first electrode group power supply means can be greatly reduced, which greatly contributes to the reduction of unnecessary radiation, malfunction, and contact breakdown.
[0046]
Further, since the charge is removed when the first electrode group power supply means is detached, it is not necessary to provide a separate means for removing the charge.
[0047]
Furthermore, a potential according to the potential gradient of the first electrode group power feeding means is induced by an electrode subgroup composed of a plurality of electrodes close to each other in the moving direction included in the first electrode group.
In addition, since the electric field is reduced only in the vicinity of the desired part in the middle of transporting the transported object, the electric field can be reduced while maintaining the attractive force, and the possibility of adverse effects of the electric field on the inkjet print head and the like can be avoided. Greatly improve the performance and reliability of the equipment.
[Brief description of the drawings]
FIG. 1 is a schematic view of application to an ink jet recording apparatus according to an embodiment of the present invention.
FIG. 2 is a schematic view of a power supply brush as a conventional power supply unit.
FIG. 3 is a schematic cross-sectional view of a conveyor belt and a power feeding unit according to an embodiment of the present invention.
FIG. 4 is a plan view (A) and a side view (B) of a conventional conveyor belt.
FIG. 5 is a plan view (A) and a side view (B) of a conveyor belt according to a first embodiment of the present invention.
FIG. 6 is a schematic diagram (A) of a power feeding unit according to the first embodiment of the present invention, and a graph (B) showing a relationship between a power feeding voltage and a power feeding position.
FIG. 7 is a schematic diagram (A) of a power feeding unit according to a second embodiment of the present invention, and a graph (B) showing a relationship between a power feeding voltage and a power feeding position.
FIG. 8 is a schematic diagram of a power feeding unit according to a third embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 to-be-conveyed body 2 Conveyance belt 3 Recording head 4a, 4b Feeding part 5 Drive roller 6, 7, 8 Support roller 9 Base film 10a, 10b of a conveyance belt Electrode group 11a, 11b on the conveyance belt of a prior art example Conveyance of this invention Electrode group on belt 12 Conductive brush 13 Power supply base material A, B, C, D, E, F, G Connection terminal

Claims (16)

A moving body that moves in the transport direction of the transported body;
A first electrode group comprising a plurality of electrodes that are provided in the transport direction in the transport direction and that move with the mobile body ;
A plurality of movable bodies provided in the transport direction, moving together with the movable body, and another electrode group having a potential difference with the first electrode group, and
In the electrostatic transport apparatus that attracts and transports the transported body to the moving body with an electrostatic force generated by a potential difference between the first electrode group and the other electrode group,
Comprising a first electrode group feeding means for applying a voltage in contact with said first electrode group of the electrode which is moving part of the movement path of the moving body,
The electrostatic transport apparatus, wherein the first electrode group power supply unit has a potential gradient in a moving direction of the moving body, and induces a potential having a gradient in the moving direction with respect to the first electrode group.   The electrostatic transport apparatus according to claim 1, wherein the first electrode group includes a small electrode group composed of a plurality of electrodes provided close to each other in the moving direction.   The electrostatic transport apparatus according to claim 1, wherein the first electrode group power supply unit has a potential gradient in the moving direction at one or a plurality of positions in the moving direction. The first electrode group power supply means has a plurality of conductive contact power supply members in contact with the first electrode group and an extension in the moving direction, and applies and holds a voltage to the contact power supply member. A holding base, and a plurality of connection terminals for supplying a predetermined voltage to the holding base,
Apply different voltages from the plurality of connection terminals,
The electrostatic transfer device according to claim 1, wherein at least a portion of the holding base material that generates a potential gradient in the moving direction is formed of a material having a large specific resistance.   The electrostatic transfer device according to claim 4, wherein a plurality of power supplies are connected to the plurality of connection terminals.   The electrostatic transfer device according to claim 4, wherein any one of the connection terminals is grounded via a resistor.   The other electrode group is in contact with a second electrode group power feeding means different from the first electrode power feeding means at a part of the moving path of the moving body, and is grounded via the second electrode group power feeding means. The electrostatic transfer device according to claim 1, further comprising a second electrode group including a plurality of electrodes.   The other electrode group contacts a second electrode group power feeding means different from the first electrode group power feeding means in a part of the moving path of the moving body, and a predetermined voltage is applied by the second electrode group power feeding means. The electrostatic transfer device according to claim 1, further comprising a second electrode group. The other electrode group is in contact with a second electrode group power feeding unit different from the first electrode group power feeding unit in a part of the moving path of the moving body, and a voltage is applied by the second electrode group power feeding unit. Including a second electrode group;
The said 2nd electrode group electric power feeding means has a potential gradient of the moving direction of the said mobile body, and induces the electric potential which has a gradient in the said moving direction with respect to the said 2nd electrode group. The electrostatic conveyance apparatus in any one of. In an image forming apparatus comprising: an image forming unit that forms an image on a recording medium; and a conveying unit for the recording medium that includes the image forming unit on a conveyance path.
9. An image forming apparatus comprising: the electrostatic transport device according to claim 1 as the transport unit that transports the recording medium as the transport target. The image forming apparatus according to claim 10, wherein the first electrode group power feeding unit has a potential gradient in which an electric field in the vicinity of the image forming unit is small . In an image forming apparatus comprising: an image forming unit that forms an image on a recording medium; and a conveying unit for the recording medium that includes the image forming unit on a conveyance path.
An image forming apparatus comprising: the electrostatic conveyance device according to claim 9 as the conveyance unit that conveys the recording medium as the conveyance target. 13. The image forming apparatus according to claim 12, wherein at least one of the first electrode group power supply unit and the second electrode group power supply unit has a potential gradient with a small electric field in the vicinity of the image forming unit. The electrostatic transport apparatus according to claim 1, wherein the first electrode group power feeding unit has a potential gradient with a small electric field at an upstream end in a moving direction of the moving body. The at least one of the first electrode group power supply means and the second electrode group power supply means has a potential gradient with a small electric field at the upstream end in the moving direction of the moving body. Image forming apparatus. A conveying belt for conveying a recording medium;
A plurality of first electrode groups provided in the moving direction of the conveyor belt, the first electrode group consisting of electrodes that move with the belt;
A plurality of second electrode groups provided in the moving direction of the conveyor belt, arranged alternately with the electrodes of the first electrode group, and moved together with the belt;
A first electrode power feeding unit configured to apply a voltage to an electrode moving in a predetermined section of the transport path of the recording medium among the electrodes of the first electrode group, and the first electrode group and the second electrode group In an electrostatic conveyance apparatus that adsorbs and conveys the recording medium to the conveyance belt with an electrostatic force generated by a potential difference.
The electrostatic transfer apparatus, wherein the first electrode power supply unit applies a voltage so that an electrostatic force at an upstream end of the predetermined section is small.

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